The university's Grant & Glueck study tracked the physical and emotional wellbeing of 268 male Harvard graduates and 456 poor men growing up in Boston between 1939 and 2014. Generations of researchers analysed the brain scans, blood samples, and self-reported surveys of these individuals over the years. Robert Waldinger, professor of psychology at Harvard and the director of the center behind the study says the conclusions are simple: close relationships make or break a person's wellbeing.

So instead of focusing all your time investing in gadgets and gym passes to get on the track to a better, happier, more successful you, consider investing in close, positive relationships. It's the quality of the relationships you have rather than the quantity, so take time to nurture your bonds with your friends, family, and loved ones. These relationships promote healthy brain functioning and can even help to reduce emotional and physical pain.

As Waldinger put it in a Tedx talk last year, "The clearest message that we get from this 75-year study is this: Good relationships keep us happier and healthier. Period."